Chemical revolution

Geoffroy's 1718 Affinity Table: at the head of each column is a chemical species with which all the species below can combine. Some historians have defined this table as being the start of the chemical revolution.[1]

The chemical revolution, also called the first chemical revolution, was the early modern reformulation of chemistry that culminated in the law of conservation of mass and the oxygen theory of combustion. During the 19th and 20th century, this transformation was credited to the work of the French chemist Antoine Lavoisier (the "father of modern chemistry").[2] However, recent work on the history of early modern chemistry considers the chemical revolution to consist of gradual changes in chemical theory and practice that emerged over a period of two centuries,[3] the so-called scientific revolution took place during the sixteenth and seventeenth centuries whereas the chemical revolution took place during the seventeenth and eighteenth centuries.[4]

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Several factors led to the first chemical revolution. First, there were the forms of gravimetric analysis that emerged from alchemy and new kinds of instruments that were developed in medical and industrial contexts; in these settings, chemists increasingly challenged hypotheses that had already been presented by the ancient Greeks. For example, chemists began to assert that all structures were composed of more than the four elements of the Greeks or the eight elements of the medieval alchemists, the Irish alchemist, Robert Boyle, laid the foundations for the Chemical Revolution, with his mechanical corpuscular philosophy, which in turn relied heavily on the alchemical corpuscular theory and experimental method dating back to pseudo-Geber.[5]

Other factors included new experimental techniques and the discovery of 'fixed air' (carbon dioxide) by Joseph Black in the middle of the 18th century, this discovery was particularly important because it empirically proved that 'air' did not consist of only one substance and because it established 'gas' as an important experimental substance. Nearer the end of the 18th century, the experiments by Henry Cavendish and Joseph Priestley further proved that air is not an element and is instead composed of several different gases. Lavoisier also translated the names of chemical substance into a new nomenclatural language more appealing to scientists of the nineteenth century, such changes took place in an atmosphere in which the industrial revolution increased public interest in learning and practicing chemistry. When describing the task of reinventing chemical nomenclature, Lavoisier attempted to harness the new centrality of chemistry by making the rather hyperbolic claim that:[6]

“

We must clean house thoroughly, for they have made use of an enigmatical language peculiar to themselves, which in general presents one meaning for the adepts and another meaning for the vulgar, and at the same time contains nothing that is rationally intelligible either for the one or for the other.

Much of the reasoning behind Antoine Lavoisier being named the "father of modern chemistry" and the start of the chemical revolution lay in his ability to mathematize the field, pushing chemistry to use the experimental methods utilized in other "more exact sciences."[7] Lavoisier changed the field of chemistry by keeping meticulous balance sheets in his research, attempting to show that through the transformation of chemical species the total amount of substance was conserved. Lavoisier used instrumentation for thermometric and barometric measurements in his experiments, and collaborated with Pierre Simon de Laplace in the invention of the calorimeter, an instrument for measuring heat changes in a reaction;[7] in attempting to dismantle phlogiston theory and implement his own theory of combustion, Lavoisier utilized multiple apparatuses. These included a red-hot iron gun barrel which was designed to have water run through it and decompose, and an alteration of the apparatus which implemented a pneumatic trough at one end, a thermometer, and a barometer, the precision of his measurements was a requirement in convincing opposition of his theories about water as a compound, with instrumentation designed by himself implemented in his research.

Despite having precise measurements for his work, Lavoisier faced a large amount of opposition in his research. Proponents of phlogiston theory, such as Keir and Priestley, claimed that demonstration of facts was only applicable for raw phenomena, and that interpretation of these facts did not imply accuracy in theories, they stated that Lavoisier was attempting to impose order on observed phenomena, whereas a secondary source of validity would be required to give definitive proof of the composition of water and non-existence of phlogiston.[7]

The latter stages of the revolution was fuelled by the 1789 publication of Lavoisier's Traité Élémentaire de Chimie (Elements of Chemistry). Beginning with this publication and others to follow, Lavoisier synthesised the work of others and coined the term "oxygen". Antoine Lavoisier represented the chemical revolution not only in his publications, but also in the way he practiced chemistry. Lavoisier's work was characterized by his systematic determination of weights and his strong emphasis on precision and accuracy,[8] the law of the conservation of mass, that the weight of matter would be conserved through any reaction, was discovered by Antoine Lavoisier in the late 18th century and represented his careful conduction of research.

Lavoisier also contributed to chemistry a method of understanding combustion and respiration and proof of the composition of water by decomposition into its constituent parts, he explained the theory of combustion, and challenged the phlogiston theory with his views on caloric. The Traité incorporates notions of a "new chemistry" and describes the experiments and reasoning that led to his conclusions. Like Newton's Principia, which was the high point of the Scientific Revolution, Lavoisier's Traité can be seen as the culmination of the Chemical Revolution.

Lavoisier's work was not immediately accepted and it took several decades for it gain momentum,[9] this transition was aided by the work of Jöns Jakob Berzelius, who came up with a simplified shorthand to describe chemical compounds based on John Dalton's theory of atomic weights. Many people credit Lavoisier and his overthrow of phlogiston theory as the traditional chemical revolution, with Lavoisier marking the beginning of the revolution and John Dalton marking its culmination.

One of Lavoisier's main influences was Étienne Bonnet, abbé de Condillac. Condillac's approach to scientific research, which was the basis of Lavoisier's approach in Traité, was to demonstrate that human beings could create a mental representation of the world using gathered evidence; in Lavoisier's preface to Traité, he states

It is a maxim universally admitted in geometry, and indeed in every branch of knowledge, that, in the progress of investigation, we should proceed from known facts to what is unknown. ... In this manner, from a series of sensations, observations, and analyses, a successive train of ideas arises, so linked together, that an attentive observer may trace back to a certain point the order and connection of the whole sum of human knowledge.[10]

Lavoisier clearly ties his ideas in with those of Condillac, seeking to reform the field of chemistry, his goal in Traité was to associate the field with direct experience and observation, rather than assumption. His work defined a new foundation for the basis of chemical ideas and set a direction for the future course of chemistry.[11]

Antoine Lavoisier, in a collaborative effort with Louis Bernard Guyton de Morveau, Claude Louis Berthollet, and Antoine François de Fourcroy, published Méthode de nomenclature chimique in 1787.[12] This work established a terminology for the "new chemistry" which Lavoisier was creating, which focused on a standardized set of terms, establishment of new elements, and experimental work. Méthode established 55 elements which were substances that could not be broken down into simpler composite parts at the time of publishing. By introducing new terminology into the field, Lavoisier encouraged other chemists to adopt his theories and practices in order to use his terms and stay current in chemistry.

John G. McEvoy (2010). Historiography of the Chemical Revolution: Patterns of Interpretation in the History of Science. Pickering & Chatto. ISBN978-1-84893-030-8. See also book review by Seymour Mauskopf in HYLE--International Journal for Philosophy of Chemistry, Vol. 17, No.1 (2011), pp. 41–46.

1.
Chemistry
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Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter. Chemistry is sometimes called the science because it bridges other natural sciences, including physics. For the differences between chemistry and physics see comparison of chemistry and physics, the history of chemistry can be traced to alchemy, which had been practiced for several millennia in various parts of the world. The word chemistry comes from alchemy, which referred to a set of practices that encompassed elements of chemistry, metallurgy, philosophy, astrology, astronomy, mysticism. An alchemist was called a chemist in popular speech, and later the suffix -ry was added to this to describe the art of the chemist as chemistry, the modern word alchemy in turn is derived from the Arabic word al-kīmīā. In origin, the term is borrowed from the Greek χημία or χημεία and this may have Egyptian origins since al-kīmīā is derived from the Greek χημία, which is in turn derived from the word Chemi or Kimi, which is the ancient name of Egypt in Egyptian. Alternately, al-kīmīā may derive from χημεία, meaning cast together, in retrospect, the definition of chemistry has changed over time, as new discoveries and theories add to the functionality of the science. The term chymistry, in the view of noted scientist Robert Boyle in 1661, in 1837, Jean-Baptiste Dumas considered the word chemistry to refer to the science concerned with the laws and effects of molecular forces. More recently, in 1998, Professor Raymond Chang broadened the definition of chemistry to mean the study of matter, early civilizations, such as the Egyptians Babylonians, Indians amassed practical knowledge concerning the arts of metallurgy, pottery and dyes, but didnt develop a systematic theory. Greek atomism dates back to 440 BC, arising in works by such as Democritus and Epicurus. In 50 BC, the Roman philosopher Lucretius expanded upon the theory in his book De rerum natura, unlike modern concepts of science, Greek atomism was purely philosophical in nature, with little concern for empirical observations and no concern for chemical experiments. Work, particularly the development of distillation, continued in the early Byzantine period with the most famous practitioner being the 4th century Greek-Egyptian Zosimos of Panopolis. He formulated Boyles law, rejected the four elements and proposed a mechanistic alternative of atoms. Before his work, though, many important discoveries had been made, the Scottish chemist Joseph Black and the Dutchman J. B. English scientist John Dalton proposed the theory of atoms, that all substances are composed of indivisible atoms of matter. Davy discovered nine new elements including the alkali metals by extracting them from their oxides with electric current, british William Prout first proposed ordering all the elements by their atomic weight as all atoms had a weight that was an exact multiple of the atomic weight of hydrogen. The inert gases, later called the noble gases were discovered by William Ramsay in collaboration with Lord Rayleigh at the end of the century, thereby filling in the basic structure of the table. Organic chemistry was developed by Justus von Liebig and others, following Friedrich Wöhlers synthesis of urea which proved that organisms were, in theory

2.
Conservation of mass
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Hence, the quantity of mass is conserved over time. Thus, during any chemical reaction, nuclear reaction, or radioactive decay in an isolated system, the concept of mass conservation is widely used in many fields such as chemistry, mechanics, and fluid dynamics. e. Those completely isolated from all exchanges with the environment, in this circumstance, the mass–energy equivalence theorem states that mass conservation is equivalent to total energy conservation, which is the first law of thermodynamics. By contrast, for a closed system mass is only approximately conserved. Certain types of matter may be created or destroyed, but in all of these processes, for a discussion, see mass in general relativity. An important idea in ancient Greek philosophy was that Nothing comes from nothing, so that what exists now has always existed, no new matter can come into existence where there was none before. A further principle of conservation was stated by Epicurus who, describing the nature of the Universe, wrote that the totality of things was always such as it is now, and always will be. Jain philosophy, a non-creationist philosophy based on the teachings of Mahavira, states that the universe, the Jain text Tattvarthasutra states that a substance is permanent, but its modes are characterised by creation and destruction. A principle of the conservation of matter was also stated by Nasīr al-Dīn al-Tūsī and he wrote that A body of matter cannot disappear completely. It only changes its form, condition, composition, color and other properties, the principle of conservation of mass was first outlined by Mikhail Lomonosov in 1748. He proved it by experiments—though this is sometimes challenged, antoine Lavoisier had expressed these ideas in 1774. Others whose ideas pre-dated the work of Lavoisier include Joseph Black, Henry Cavendish, the conservation of mass was obscure for millennia because of the buoyancy effect of the Earths atmosphere on the weight of gases. For example, a piece of wood weighs less after burning, the vacuum pump also enabled the weighing of gases using scales. Once understood, the conservation of mass was of importance in progressing from alchemy to modern chemistry. His research indicated that in certain reactions the loss or gain could not have more than from 2 to 4 parts in 100,000. The difference in the accuracy aimed at and attained by Lavoisier on the one hand, in special relativity, the conservation of mass does not apply if the system is open and energy escapes. However, it continue to apply to totally closed systems. If energy cannot escape a system, its mass cannot decrease, in relativity theory, so long as any type of energy is retained within a system, this energy exhibits mass

3.
Oxygen
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Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the group on the periodic table and is a highly reactive nonmetal. By mass, oxygen is the third-most abundant element in the universe, after hydrogen, at standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. This is an important part of the atmosphere and diatomic oxygen gas constitutes 20. 8% of the Earths atmosphere, additionally, as oxides the element makes up almost half of the Earths crust. Most of the mass of living organisms is oxygen as a component of water, conversely, oxygen is continuously replenished by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. Oxygen is too reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form of oxygen, ozone, strongly absorbs ultraviolet UVB radiation, but ozone is a pollutant near the surface where it is a by-product of smog. At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft, the name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle, Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries later Leonardo da Vinci built on Philos work by observing that a portion of air is consumed during combustion and respiration, Oxygen was discovered by the Polish alchemist Sendivogius, who considered it the philosophers stone. In the late 17th century, Robert Boyle proved that air is necessary for combustion, English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. From this he surmised that nitroaereus is consumed in both respiration and combustion, Mayow observed that antimony increased in weight when heated, and inferred that the nitroaereus must have combined with it. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract De respiratione. Robert Hooke, Ole Borch, Mikhail Lomonosov, and Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element. This may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, which was then the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher, one part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx. The fact that a substance like wood gains overall weight in burning was hidden by the buoyancy of the combustion products

4.
Combustion
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Combustion in a fire produces a flame, and the heat produced can make combustion self-sustaining. Combustion is often a sequence of elementary radical reactions. Solid fuels, such as wood, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the required to produce more of them. Combustion is often hot enough that light in the form of either glowing or a flame is produced, a simple example can be seen in the combustion of hydrogen and oxygen into water vapor, a reaction commonly used to fuel rocket engines. The bond energies in the play only a minor role, since they are similar to those in the combustion products. The heat of combustion is approximately -418 kJ per mole of O2 used up in the combustion reaction, uncatalyzed combustion in air requires fairly high temperatures. Complete combustion is stoichiometric with respect to the fuel, where there is no remaining fuel, thermodynamically, the chemical equilibrium of combustion in air is overwhelmingly on the side of the products. Thus, the smoke is usually toxic and contains unburned or partially oxidized products. Since combustion is rarely clean, flue gas cleaning or catalytic converters may be required by law, fires occur naturally, ignited by lightning strikes or by volcanic products. Combustion was the first controlled chemical reaction discovered by humans, in the form of campfires and bonfires, usually, the fuel is carbon, hydrocarbons or more complicated mixtures such as wood that contains partially oxidized hydrocarbons. Combustion is also currently the only used to power rockets. Combustion is also used to destroy waste, both nonhazardous and hazardous, oxidants for combustion have high oxidation potential and include atmospheric or pure oxygen, chlorine, fluorine, chlorine trifluoride, nitrous oxide and nitric acid. For instance, hydrogen burns in chlorine to form hydrogen chloride with the liberation of heat, although usually not catalyzed, combustion can be catalyzed by platinum or vanadium, as in the contact process. In complete combustion, the reactant burns in oxygen, producing a number of products. When a hydrocarbon burns in oxygen, the reaction will yield carbon dioxide. When elements are burned, the products are primarily the most common oxides, carbon will yield carbon dioxide, sulfur will yield sulfur dioxide, and iron will yield iron oxide. Nitrogen is not considered to be a combustible substance when oxygen is the oxidant, Combustion is not necessarily favorable to the maximum degree of oxidation, and it can be temperature-dependent. For example, sulfur trioxide is not produced quantitatively by the combustion of sulfur, NOx species appear in significant amounts above about 2,800 °F, and more is produced at higher temperatures

5.
Antoine Lavoisier
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Antoine-Laurent de Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and had a large influence on both the history of chemistry and the history of biology. He is widely considered in popular literature as the father of modern chemistry and it is generally accepted that Lavoisiers great accomplishments in chemistry largely stem from his changing the science from a qualitative to a quantitative one. Lavoisier is most noted for his discovery of the role oxygen plays in combustion and he recognized and named oxygen and hydrogen and opposed the phlogiston theory. Lavoisier helped construct the system, wrote the first extensive list of elements. He predicted the existence of silicon and was also the first to establish that sulfur was an element rather than a compound and he discovered that, although matter may change its form or shape, its mass always remains the same. Lavoisier was a member of a number of aristocratic councils. All of these political and economic activities enabled him to fund his scientific research, at the height of the French Revolution, he was accused by Jean-Paul Marat of selling adulterated tobaccoand of other crimes, and was eventually guillotined a year after Marats death. Antoine-Laurent Lavoisier was born to a family of the nobility in Paris on 26 August 1743. The son of an attorney at the Parliament of Paris, he inherited a fortune at the age of five with the passing of his mother. Lavoisier began his schooling at the Collège des Quatre-Nations, University of Paris in Paris in 1754 at the age of 11, in his last two years at the school, his scientific interests were aroused, and he studied chemistry, botany, astronomy, and mathematics. Lavoisier entered the school of law, where he received a degree in 1763. Lavoisier received a law degree and was admitted to the bar, however, he continued his scientific education in his spare time. Lavoisiers education was filled with the ideals of the French Enlightenment of the time and he attended lectures in the natural sciences. Lavoisiers devotion and passion for chemistry were largely influenced by Étienne Condillac and his first chemical publication appeared in 1764. From 1763 to 1767, he studied geology under Jean-Étienne Guettard, in collaboration with Guettard, Lavoisier worked on a geological survey of Alsace-Lorraine in June 1767. In 1768 Lavoisier received an appointment to the Academy of Sciences. In 1769, he worked on the first geological map of France, on behalf of the Ferme générale Lavoisier commissioned the building of a wall around Paris so that customs duties could be collected from those transporting goods into and out of the city. Lavoisier attempted to introduce reforms in the French monetary and taxation system to help the peasants, Lavoisier consolidated his social and economic position when, in 1771 at age 28, he married Marie-Anne Pierrette Paulze, the 13-year-old daughter of a senior member of the Ferme générale

6.
Scientific revolution
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While its dates are debated, the publication in 1543 of Nicolaus Copernicuss De revolutionibus orbium coelestium is often cited as marking the beginning of the scientific revolution. By the end of the 18th century, the revolution had given way to the Age of Reflection. Great advances in science have been termed revolutions since the 18th century, in 1747, Clairaut wrote that Newton was said in his own lifetime to have created a revolution. The word was used in the preface to Lavoisiers 1789 work announcing the discovery of oxygen. Few revolutions in science have immediately excited so much general notice as the introduction of the theory of oxygen, lavoisier saw his theory accepted by all the most eminent men of his time, and established over a great part of Europe within a few years from its first promulgation. In the 19th century, William Whewell described the revolution in science itself -- the scientific method -- that had taken place in the 15th–16th century. This gave rise to the view of the scientific revolution today, A new view of nature emerged. Science became a discipline, distinct from both philosophy and technology and came to be regarded as having utilitarian goals. The scientific revolution is traditionally assumed to start with the Copernican Revolution, in the 20th century, Alexandre Koyré introduced the term scientific revolution, centering his analysis on Galileo. The term was popularized by Butterfield in his Origins of Modern Science, the scientific revolution led to the establishment of several modern sciences. In 1984, Joseph Ben-David wrote, Rapid accumulation of knowledge, the new kind of scientific activity emerged only in a few countries of Western Europe, and it was restricted to that small area for about two hundred years. Many contemporary writers and modern historians claim that there was a change in world view. Looms so large as the origin both of the modern world and of the modern mentality that our customary periodization of European history has become an anachronism. Some scholars have noted a direct tie between particular aspects of traditional Christianity and the rise of science, the Aristotelian tradition was still an important intellectual framework in the 17th century, although by that time natural philosophers had moved away from much of it. Key scientific ideas dating back to classical antiquity had changed drastically over the years, the ideas that remained, which were transformed fundamentally during the scientific revolution, include, Aristotles cosmology that placed the Earth at the center of a spherical hierarchic cosmos. The terrestrial and celestial regions were made up of different elements which had different kinds of natural movement, the terrestrial region, according to Aristotle, consisted of concentric spheres of the four elements—earth, water, air, and fire. All bodies naturally moved in straight lines until they reached the sphere appropriate to their elemental composition—their natural place, all other terrestrial motions were non-natural, or violent. The celestial region was made up of the element, aether

7.
Classical element
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Ancient cultures in Egypt, Babylonia, Japan, Tibet, and India had similar lists, sometimes referring in local languages to air as wind and the fifth element as void. The Chinese Wu Xing system lists Wood, Fire, Earth, Metal and these different cultures and even individual philosophers had widely varying explanations concerning their attributes and how they related to observable phenomena as well as cosmology. Sometimes these theories overlapped with mythology and were personified in deities, some of these interpretations included atomism but other interpretations considered the elements to be divisible into infinitely small pieces without changing their nature. Centuries of empirical investigation have proven that all the ancient systems were incorrect explanations of the physical world. It is now known that atomic theory is an explanation, and that atoms can be classified into more than a hundred chemical elements such as oxygen, iron. These elements form chemical compounds and mixtures, and under different temperatures and pressures, the concept of the five elements formed a basis of analysis in both Hinduism and Buddhism. In Hinduism, particularly in a context, the four states-of-matter describe matter. Similar lists existed in ancient China and Japan, in Buddhism the four great elements, to which two others are sometimes added, are not viewed as substances, but as categories of sensory experience. A Greek text called the Kore Kosmou ascribed to Hermes Trismegistus, names the four fire, water, air. And, on the contrary, again some are made enemies of fire, and some of water, some of earth, and some of air, and some of two of them, and some of three, and some of all. For instance, son, the locust and all flies flee fire, the eagle and the hawk and all high-flying birds flee water, fish, air and earth, the snake avoids the open air. Not that some of the animals as well do not love fire, for instance salamanders and it is because one or another of the elements doth form their bodies outer envelope. Each soul, accordingly, while it is in its body is weighted and constricted by these four. According to Galen, these elements were used by Hippocrates in describing the body with an association with the four humours, yellow bile, black bile, blood. Medical care was flexible and primarily about helping the patient stay in or return to his/her own personal natural balanced state. In other Babylonian texts these phenomena are considered independent of their association with deities, though they are not treated as the component elements of the universe, the five elements are associated with the five senses, and act as the gross medium for the experience of sensations. The basest element, earth, created using all the elements, can be perceived by all five senses – hearing, touch, sight, taste. The next higher element, water, has no odor but can be heard, felt, seen, next comes fire, which can be heard, felt and seen

8.
Alchemy
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Alchemy is a philosophical and protoscientific tradition practiced throughout Europe, Egypt and Asia. It aimed to purify, mature, and perfect certain objects, the perfection of the human body and soul was thought to permit or result from the alchemical magnum opus and, in the Hellenistic and western tradition, the achievement of gnosis. In Europe, the creation of a stone was variously connected with all of these projects. In English, the term is limited to descriptions of European alchemy, but similar practices existed in the Far East, the Indian subcontinent. In Europe, following the 12th-century Renaissance produced by the translation of Islamic works on science, Islamic and European alchemists developed a structure of basic laboratory techniques, theory, terminology, and experimental method, some of which are still in use today. However, they continued antiquitys belief in four elements and guarded their work in secrecy including cyphers and their work was guided by Hermetic principles related to magic, mythology, and religion. The latter interests historians of esotericism, psychologists, and some philosophers, the subject has also made an ongoing impact on literature and the arts. The word alchemy was borrowed from Old French alquemie, alkimie, taken from Medieval Latin alchymia, the Arabic word is borrowed from Late Greek chēmeía, chēmía, with the agglutination of the Arabic definite article al-. This ancient Greek word was derived from the early Greek name for Egypt, Chēmia, based on the Egyptian name for Egypt, the Medieval Latin form was influenced by Greek chymeia meaning ‘mixture’ and referring to pharmaceutical chemistry. Alchemy covers several philosophical traditions spanning some four millennia and three continents and these traditions general penchant for cryptic and symbolic language makes it hard to trace their mutual influences and genetic relationships. It is still a question whether these three strands share a common origin, or to what extent they influenced each other. Here, elements of technology, religion, mythology, and Hellenistic philosophy, each with their own much longer histories, Zosimos of Panopolis wrote the oldest known books on alchemy, while Mary the Jewess is credited as being the first non-fictitious Western alchemist. They wrote in Greek and lived in Egypt under Roman rule, mythology – Zosimos of Panopolis asserted that alchemy dated back to Pharaonic Egypt where it was the domain of the priestly class, though there is little to no evidence for his assertion. Alchemical writers used Classical figures from Greek, Roman, and Egyptian mythology to illuminate their works and these included the pantheon of gods related to the Classical planets, Isis, Osiris, Jason, and many others. The central figure in the mythology of alchemy is Hermes Trismegistus and his name is derived from the god Thoth and his Greek counterpart Hermes. Hermes and his caduceus or serpent-staff, were among alchemys principal symbols, according to Clement of Alexandria, he wrote what were called the forty-two books of Hermes, covering all fields of knowledge. The Hermetica of Thrice-Great Hermes is generally understood to form the basis for Western alchemical philosophy and practice and these writings were collected in the first centuries of the common era. Technology – The dawn of Western alchemy is sometimes associated with that of metallurgy, Many writings were lost when the emperor Diocletian ordered the burning of alchemical books after suppressing a revolt in Alexandria

9.
Robert Boyle
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Robert William Boyle FRS was an Anglo-Irish natural philosopher, chemist, physicist and inventor born in Lismore, County Waterford, Ireland. Boyle is largely regarded today as the first modern chemist, and therefore one of the founders of modern chemistry, and one of the pioneers of modern experimental scientific method. He is best known for Boyles law, which describes the proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system. Among his works, The Sceptical Chymist is seen as a book in the field of chemistry. He was a devout and pious Anglican and is noted for his writings in theology, Boyle was born in Lismore Castle, in County Waterford, Ireland, the seventh son and fourteenth child of Richard Boyle, 1st Earl of Cork, and Catherine Fenton. Richard Boyle arrived in Dublin from England in 1588 during the Tudor plantations of Ireland and he had amassed enormous landholdings by the time Robert was born. As a child, Boyle was fostered to a local family, Boyle received private tutoring in Latin, Greek, and French and when he was eight years old, following the death of his mother, he was sent to Eton College in England. His fathers friend, Sir Henry Wotton, was then the provost of the college, during this time, his father hired a private tutor, Robert Carew, who had knowledge of Irish, to act as private tutor to his sons in Eton. After spending over three years at Eton, Robert travelled abroad with a French tutor and they visited Italy in 1641 and remained in Florence during the winter of that year studying the paradoxes of the great star-gazer Galileo Galilei, who was elderly but still living in 1641. Boyle returned to England from continental Europe in mid-1644 with a keen interest in scientific research and his father had died the previous year and had left him the manor of Stalbridge in Dorset, England and substantial estates in County Limerick in Ireland that he had acquired. They met frequently in London, often at Gresham College, having made several visits to his Irish estates beginning in 1647, Robert moved to Ireland in 1652 but became frustrated at his inability to make progress in his chemical work. In one letter, he described Ireland as a country where chemical spirits were so misunderstood. In 1654, Boyle left Ireland for Oxford to pursue his work more successfully, an inscription can be found on the wall of University College, Oxford the High Street at Oxford, marking the spot where Cross Hall stood until the early 19th century. It was here that Boyle rented rooms from the apothecary who owned the Hall. An account of Boyles work with the air pump was published in 1660 under the title New Experiments Physico-Mechanical, Touching the Spring of the Air, the person who originally formulated the hypothesis was Henry Power in 1661. Boyle in 1662 included a reference to a written by Power. In continental Europe the hypothesis is attributed to Edme Mariotte. In 1680 he was elected president of the society, but declined the honour from a scruple about oaths and they are extraordinary because all but a few of the 24 have come true

10.
Scientific method
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The scientific method is a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry is commonly based on empirical or measurable evidence subject to specific principles of reasoning, experiments need to be designed to test hypotheses. The most important part of the method is the experiment. The scientific method is a process, which usually begins with observations about the natural world. Human beings are naturally inquisitive, so often come up with questions about things they see or hear. The best hypotheses lead to predictions that can be tested in various ways, in general, the strongest tests of hypotheses come from carefully controlled and replicated experiments that gather empirical data. Depending on how well the tests match the predictions, the hypothesis may require refinement. If a particular hypothesis becomes very well supported a theory may be developed. Although procedures vary from one field of inquiry to another, identifiable features are shared in common between them. The overall process of the method involves making conjectures, deriving predictions from them as logical consequences. A hypothesis is a conjecture, based on knowledge obtained while formulating the question, the hypothesis might be very specific or it might be broad. Scientists then test hypotheses by conducting experiments, the purpose of an experiment is to determine whether observations agree with or conflict with the predictions derived from a hypothesis. Experiments can take anywhere from a college lab to CERNs Large Hadron Collider. There are difficulties in a statement of method, however. Though the scientific method is presented as a fixed sequence of steps. Not all steps take place in scientific inquiry, and are not always in the same order. Some philosophers and scientists have argued there is no scientific method, such as Lee Smolin. Nola and Sankey remark that For some, the idea of a theory of scientific method is yester-years debate

11.
Pseudo-Geber
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Pseudo-Geber is the name assigned by modern scholars to an anonymous European alchemist born in the 13th century who wrote books on alchemy and metallurgy in Latin under the pen name of Geber. Geber is the shortened and Latinised form of the name Jābir ibn Hayyān, in Europe for many centuries from the 14th century onward it was assumed that Geber was identical with Jabir ibn Hayyan and that the books of Geber had been translated from Arabic. Arabic alchemy was held in esteem by 13th century European alchemists. Pseudo-Geber adopted the name of his illustrious Arabic predecessor to attach more stature to his own work, the practice of adopting the name of an illustrious predecessor is called pseudepigraphy, and it was not uncommon in the medieval era. Similarly, a variety of medieval writings were distributed with the illustrious Aristotle as the stated author that were not written by the original authentic Aristotle. In the domain of alchemy and metallurgy in late medieval Europe, the following set of books is called the Pseudo-Geber Corpus. The books were published by printing press several times in the first half of the 16th century and they were in circulation in manuscript for roughly 200 years beforehand. The stated author is Geber or Geber Arabis, and it is stated in some copies that the translator is Rodogerus Hispalensis, liber fornacum, De investigatione perfectionis, and De inventione veritatis. The Summa Perfectionis in particular was one of the most widely read books in western Europe in the late medieval period. The next three books on the list above are shorter and are, to a degree, condensations of the material in the Summa Perfectionis. Their author is not the same as the others, but it is not certain that the first four have the author either. As mentioned, the Pseudo-Geber corpus was assumed to be translated from Arabic throughout the medieval and this assumption was reversed in the late 19th century by the studies of Kopp, Hoefer, Berthelot, and Lippmann. The corpus is clearly influenced by medieval Arabic writers, for example, there is no mention in the 13th century writings of Albertus Magnus and Roger Bacon. The chemistry historian J. C. Brown asserted in 1920, An important point of evidence is the absence in the Arabic texts of the new, nitric acid, aqua regia, oil of vitriol, silver nitrate. Aqua regia is a mixture of acid and hydrochloric acid. Vladimir Karpenko and John A. Norris, in 2001, assert that its first documented occurrence is in Pseudo-Geber, in 2005, the historian Ahmad Y. The identity of the proposed Latin author remains a mystery and he may have lived in Italy or Spain, or both. Some books in the Geber corpus may have been written by authors that post-date the author of the Summa Perfectionis, as mentioned already, the contents of most of the other books in the corpus are mostly recapitulations of the Summa Perfectionis

12.
Experiment
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An experiment is a procedure carried out to support, refute, or validate a hypothesis. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated, experiments vary greatly in goal and scale, but always rely on repeatable procedure and logical analysis of the results. There also exists natural experimental studies, a child may carry out basic experiments to understand gravity, while teams of scientists may take years of systematic investigation to advance their understanding of a phenomenon. Experiments and other types of activities are very important to student learning in the science classroom. Experiments can raise test scores and help a student become more engaged and interested in the material they are learning, experiments can vary from personal and informal natural comparisons, to highly controlled. Uses of experiments vary considerably between the natural and human sciences, experiments typically include controls, which are designed to minimize the effects of variables other than the single independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements, scientific controls are a part of the scientific method. Ideally, all variables in an experiment are controlled and none are uncontrolled, in such an experiment, if all controls work as expected, it is possible to conclude that the experiment works as intended, and that results are due to the effect of the tested variable. In the scientific method, an experiment is a procedure that arbitrates between competing models or hypotheses. Researchers also use experimentation to test existing theories or new hypotheses to support or disprove them, an experiment usually tests a hypothesis, which is an expectation about how a particular process or phenomenon works. However, an experiment may also aim to answer a question, without a specific expectation about what the experiment reveals. If an experiment is conducted, the results usually either support or disprove the hypothesis. According to some philosophies of science, an experiment can never prove a hypothesis, on the other hand, an experiment that provides a counterexample can disprove a theory or hypothesis. An experiment must also control the possible confounding factors—any factors that would mar the accuracy or repeatability of the experiment or the ability to interpret the results, confounding is commonly eliminated through scientific controls and/or, in randomized experiments, through random assignment. In engineering and the sciences, experiments are a primary component of the scientific method. They are used to test theories and hypotheses about how physical processes work under particular conditions, typically, experiments in these fields focus on replication of identical procedures in hopes of producing identical results in each replication. In medicine and the sciences, the prevalence of experimental research varies widely across disciplines. In contrast to norms in the sciences, the focus is typically on the average treatment effect or another test statistic produced by the experiment

13.
Henry Cavendish
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Henry Cavendish FRS was a British natural philosopher, scientist, and an important experimental and theoretical chemist and physicist. Cavendish is noted for his discovery of hydrogen or what he called inflammable air and he described the density of inflammable air, which formed water on combustion, in a 1766 paper On Factitious Airs. Antoine Lavoisier later reproduced Cavendishs experiment and gave the element its name and his experiment to measure the density of the Earth has come to be known as the Cavendish experiment. Henry Cavendish was born on 10 October 1731 in Nice, where his family was living at the time. His mother was Lady Anne Grey, fourth daughter of Henry Grey, 1st Duke of Kent, the family traces its lineage across eight centuries to Norman times and was closely connected to many aristocratic families of Great Britain. His mother died in 1733, three months after the birth of her son, Frederick, and shortly before Henry’s second birthday. At age 11, Henry attended Hackney Academy, a school near London. At age 18 he entered the University of Cambridge in St Peters College, now known as Peterhouse and he then lived with his father in London, where he soon had his own laboratory. Lord Charles Cavendish spent his life, first, in politics and then increasingly in science, in 1758, he took Henry to meetings of the Royal Society and also to dinners of the Royal Society Club. In 1760, Henry Cavendish was elected to both groups, and he was assiduous in his attendance thereafter. He took virtually no part in politics, but followed his father in to science, through his researches and he was active in the Council of the Royal Society of London. His first paper, Factitious Airs, appeared in 1766, in 1773, Henry joined his father as an elected trustee of the British Museum, to which he devoted a good deal of time and effort. About the time of his fathers death, Cavendish began to work closely with Charles Blagden, in return, Blagden helped to keep the world at a distance from Cavendish. Cavendish published no books and few papers, but he achieved much, several areas of research, including mechanics, optics, and magnetism, feature extensively in his manuscripts, but they scarcely feature in his published work. Cavendish is considered to be one of the so-called pneumatic chemists of the eighteenth and nineteenth centuries, along with, for example, Joseph Priestley, Joseph Black, and Daniel Rutherford. Cavendish found that a definite, peculiar, and highly inflammable gas and this gas was in fact hydrogen, which Cavendish correctly guessed was proportioned to two in one water. Although others, such as Robert Boyle, had prepared hydrogen gas earlier, also, by dissolving alkalis in acids, Cavendish made fixed air, which he collected, along with other gases, in bottles inverted over water or mercury. He then measured their solubility in water and their specific gravity, Cavendish was awarded the Royal Society’s Copley Medal for this paper

14.
Joseph Priestley
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He is usually credited with the discovery of oxygen, having isolated it in its gaseous state, although Carl Wilhelm Scheele and Antoine Lavoisier also have a claim to the discovery. However, Priestleys determination to defend phlogiston theory and to reject what would become the chemical revolution eventually left him isolated within the scientific community, Priestleys science was integral to his theology, and he consistently tried to fuse Enlightenment rationalism with Christian theism. In his metaphysical texts, Priestley attempted to combine theism, materialism, and determinism and he believed that a proper understanding of the natural world would promote human progress and eventually bring about the Christian Millennium. Priestley, who believed in the free and open exchange of ideas, advocated toleration and equal rights for religious Dissenters. He spent his last ten years in Northumberland County, Pennsylvania and these educational writings were among Priestleys most popular works. Priestley was born to an established English Dissenting family in Birstall and he was the oldest of six children born to Mary Swift and Jonas Priestley, a finisher of cloth. To ease his mothers burdens, Priestley was sent to live with his grandfather around the age of one and he returned home, five years later, after his mother died. When his father remarried in 1741, Priestley went to live with his aunt and uncle, during his youth, Priestley attended local schools where he learned Greek, Latin, and Hebrew. Around 1749, Priestley became seriously ill and believed he was dying, raised as a devout Calvinist, he believed a conversion experience was necessary for salvation, but doubted he had had one. This emotional distress eventually led him to question his upbringing, causing him to reject election. As a result, the elders of his church, the Independent Upper Chapel of Heckmondwike. Priestleys illness left him with a permanent stutter and he gave up any thoughts of entering the ministry at that time, in preparation for joining a relative in trade in Lisbon, he studied French, Italian, and German in addition to Aramaic, and Arabic. Priestley eventually decided to return to his studies and, in 1752, matriculated at Daventry. Because he had read widely, Priestley was allowed to skip the first two years of coursework. He continued his study, this, together with the liberal atmosphere of the school, shifted his theology further leftward. Abhorring dogma and religious mysticism, Rational Dissenters emphasised the rational analysis of the natural world, Priestley later wrote that the book that influenced him the most, save the Bible, was David Hartleys Observations on Man. Hartleys psychological, philosophical, and theological treatise postulated a theory of mind. Hartley aimed to construct a Christian philosophy in both religious and moral facts could be scientifically proven, a goal that would occupy Priestley for his entire life

15.
Atmosphere of Earth
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The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earths gravity. The atmosphere of Earth protects life on Earth by absorbing solar radiation, warming the surface through heat retention. By volume, dry air contains 78. 09% nitrogen,20. 95% oxygen,0. 93% argon,0. 04% carbon dioxide, and small amounts of other gases. Air also contains an amount of water vapor, on average around 1% at sea level. The atmosphere has a mass of about 5. 15×1018 kg, the atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. The Kármán line, at 100 km, or 1. 57% of Earths radius, is used as the border between the atmosphere and outer space. Atmospheric effects become noticeable during atmospheric reentry of spacecraft at an altitude of around 120 km, several layers can be distinguished in the atmosphere, based on characteristics such as temperature and composition. The study of Earths atmosphere and its processes is called atmospheric science, early pioneers in the field include Léon Teisserenc de Bort and Richard Assmann. The three major constituents of air, and therefore of Earths atmosphere, are nitrogen, oxygen, water vapor accounts for roughly 0. 25% of the atmosphere by mass. The remaining gases are often referred to as gases, among which are the greenhouse gases, principally carbon dioxide, methane, nitrous oxide. Filtered air includes trace amounts of other chemical compounds. Various industrial pollutants also may be present as gases or aerosols, such as chlorine, fluorine compounds, sulfur compounds such as hydrogen sulfide and sulfur dioxide may be derived from natural sources or from industrial air pollution. In general, air pressure and density decrease with altitude in the atmosphere, however, temperature has a more complicated profile with altitude, and may remain relatively constant or even increase with altitude in some regions. In this way, Earths atmosphere can be divided into five main layers, excluding the exosphere, Earth has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere. It extends from the exobase, which is located at the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km where it merges into the solar wind. This layer is composed of extremely low densities of hydrogen, helium and several heavier molecules including nitrogen, oxygen. The atoms and molecules are so far apart that they can travel hundreds of kilometers without colliding with one another, thus, the exosphere no longer behaves like a gas, and the particles constantly escape into space. These free-moving particles follow ballistic trajectories and may migrate in and out of the magnetosphere or the solar wind, the exosphere is located too far above Earth for any meteorological phenomena to be possible

16.
Chemical element
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A chemical element or element is a species of atoms having the same number of protons in their atomic nuclei. There are 118 elements that have identified, of which the first 94 occur naturally on Earth with the remaining 24 being synthetic elements. There are 80 elements that have at least one stable isotope and 38 that have exclusively radioactive isotopes, iron is the most abundant element making up Earth, while oxygen is the most common element in the Earths crust. Chemical elements constitute all of the matter of the universe. The two lightest elements, hydrogen and helium, were formed in the Big Bang and are the most common elements in the universe. The next three elements were formed mostly by cosmic ray spallation, and are rarer than those that follow. Formation of elements with from 6 to 26 protons occurred and continues to occur in main sequence stars via stellar nucleosynthesis, the high abundance of oxygen, silicon, and iron on Earth reflects their common production in such stars. The term element is used for atoms with a number of protons as well as for a pure chemical substance consisting of a single element. A single element can form multiple substances differing in their structure, when different elements are chemically combined, with the atoms held together by chemical bonds, they form chemical compounds. Only a minority of elements are found uncombined as relatively pure minerals, among the more common of such native elements are copper, silver, gold, carbon, and sulfur. All but a few of the most inert elements, such as gases and noble metals, are usually found on Earth in chemically combined form. While about 32 of the elements occur on Earth in native uncombined forms. For example, atmospheric air is primarily a mixture of nitrogen, oxygen, and argon, the history of the discovery and use of the elements began with primitive human societies that found native elements like carbon, sulfur, copper and gold. Later civilizations extracted elemental copper, tin, lead and iron from their ores by smelting, using charcoal, alchemists and chemists subsequently identified many more, almost all of the naturally occurring elements were known by 1900. Save for unstable radioactive elements with short half-lives, all of the elements are available industrially, almost all other elements found in nature were made by various natural methods of nucleosynthesis. On Earth, small amounts of new atoms are produced in nucleogenic reactions, or in cosmogenic processes. Of the 94 naturally occurring elements, those with atomic numbers 1 through 82 each have at least one stable isotope, Isotopes considered stable are those for which no radioactive decay has yet been observed. Elements with atomic numbers 83 through 94 are unstable to the point that radioactive decay of all isotopes can be detected, the very heaviest elements undergo radioactive decay with half-lives so short that they are not found in nature and must be synthesized

17.
Gas
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Gas is one of the four fundamental states of matter. A pure gas may be made up of atoms, elemental molecules made from one type of atom. A gas mixture would contain a variety of pure gases much like the air, what distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colorless gas invisible to the human observer, the interaction of gas particles in the presence of electric and gravitational fields are considered negligible as indicated by the constant velocity vectors in the image. One type of commonly known gas is steam, the gaseous state of matter is found between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention, high-density atomic gases super cooled to incredibly low temperatures are classified by their statistical behavior as either a Bose gas or a Fermi gas. For a comprehensive listing of these states of matter see list of states of matter. The only chemical elements which are stable multi atom homonuclear molecules at temperature and pressure, are hydrogen, nitrogen and oxygen. These gases, when grouped together with the noble gases. Alternatively they are known as molecular gases to distinguish them from molecules that are also chemical compounds. The word gas is a neologism first used by the early 17th-century Flemish chemist J. B. van Helmont, according to Paracelsuss terminology, chaos meant something like ultra-rarefied water. An alternative story is that Van Helmonts word is corrupted from gahst and these four characteristics were repeatedly observed by scientists such as Robert Boyle, Jacques Charles, John Dalton, Joseph Gay-Lussac and Amedeo Avogadro for a variety of gases in various settings. Their detailed studies ultimately led to a relationship among these properties expressed by the ideal gas law. Gas particles are separated from one another, and consequently have weaker intermolecular bonds than liquids or solids. These intermolecular forces result from interactions between gas particles. Like-charged areas of different gas particles repel, while oppositely charged regions of different gas particles attract one another, transient, randomly induced charges exist across non-polar covalent bonds of molecules and electrostatic interactions caused by them are referred to as Van der Waals forces. The interaction of these forces varies within a substance which determines many of the physical properties unique to each gas. A comparison of boiling points for compounds formed by ionic and covalent bonds leads us to this conclusion, the drifting smoke particles in the image provides some insight into low pressure gas behavior

18.
Industrial Revolution
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The Industrial Revolution was the transition to new manufacturing processes in the period from about 1760 to sometime between 1820 and 1840. The Industrial Revolution began in Great Britain and most of the important technological innovations were British, aided by these legal and cultural foundations, an entrepreneurial spirit and consumer revolution drove industrialisation in Britain, which would be emulated in countries around the world. A change in marrying patterns to getting married later made able to accumulate more human capital during their youth. The Industrial Revolution marks a turning point in history, almost every aspect of daily life was influenced in some way. In particular, average income and population began to exhibit unprecedented sustained growth, mechanised textile production spread from Great Britain to continental Europe in the early 19th century, with important centres of textiles, iron and coal emerging in Belgium, and later in France. Since then industrialisation has spread throughout much of the world, the precise start and end of the Industrial Revolution is still debated among historians, as is the pace of economic and social changes. Economic historians are in agreement that the onset of the Industrial Revolution is the most important event in the history of humanity since the domestication of animals and plants. The term Industrial Revolution applied to change was becoming more common by the late 1830s. Friedrich Engels in The Condition of the Working Class in England in 1844 spoke of an industrial revolution, however, although Engels wrote in the 1840s, his book was not translated into English until the late 1800s, and his expression did not enter everyday language until then. Credit for popularising the term may be given to Arnold Toynbee, some historians, such as John Clapham and Nicholas Crafts, have argued that the economic and social changes occurred gradually and the term revolution is a misnomer. This is still a subject of debate among some historians, the commencement of the Industrial Revolution is closely linked to a small number of innovations, beginning in the second half of the 18th century. By the 1830s the following gains had been made in important technologies, Textiles – mechanised cotton spinning powered by steam or water greatly increased the output of a worker, the power loom increased the output of a worker by a factor of over 40. The cotton gin increased productivity of removing seed from cotton by a factor of 50, large gains in productivity also occurred in spinning and weaving of wool and linen, but they were not as great as in cotton. Steam power – the efficiency of steam engines increased so that they used between one-fifth and one-tenth as much fuel, the adaptation of stationary steam engines to rotary motion made them suitable for industrial uses. The high pressure engine had a power to weight ratio. Steam power underwent an expansion after 1800. Iron making – the substitution of coke for charcoal greatly lowered the fuel cost for pig iron, using coke also allowed larger blast furnaces, resulting in economies of scale. The cast iron blowing cylinder was first used in 1760 and it was later improved by making it double acting, which allowed higher furnace temperatures

19.
Pierre-Simon Laplace
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Pierre-Simon, marquis de Laplace was an influential French scholar whose work was important to the development of mathematics, statistics, physics and astronomy. He summarized and extended the work of his predecessors in his five-volume Mécanique Céleste and this work translated the geometric study of classical mechanics to one based on calculus, opening up a broader range of problems. In statistics, the Bayesian interpretation of probability was developed mainly by Laplace, Laplace formulated Laplaces equation, and pioneered the Laplace transform which appears in many branches of mathematical physics, a field that he took a leading role in forming. The Laplacian differential operator, widely used in mathematics, is named after him. Laplace is remembered as one of the greatest scientists of all time, sometimes referred to as the French Newton or Newton of France, he has been described as possessing a phenomenal natural mathematical faculty superior to that of any of his contemporaries. Laplace became a count of the Empire in 1806 and was named a marquis in 1817, Laplace was born in Beaumont-en-Auge, Normandy on 23 March 1749, a village four miles west of Pont lEveque in Normandy. According to W. W. Rouse Ball, His father, Pierre de Laplace and his great-uncle, Maitre Oliver de Laplace, had held the title of Chirurgien Royal. It would seem that from a pupil he became an usher in the school at Beaumont, however, Karl Pearson is scathing about the inaccuracies in Rouse Balls account and states, Indeed Caen was probably in Laplaces day the most intellectually active of all the towns of Normandy. It was here that Laplace was educated and was provisionally a professor and it was here he wrote his first paper published in the Mélanges of the Royal Society of Turin, Tome iv. 1766–1769, at least two years before he went at 22 or 23 to Paris in 1771, thus before he was 20 he was in touch with Lagrange in Turin. He did not go to Paris a raw self-taught country lad with only a peasant background, the École Militaire of Beaumont did not replace the old school until 1776. His parents were from comfortable families and his father was Pierre Laplace, and his mother was Marie-Anne Sochon. The Laplace family was involved in agriculture until at least 1750, Pierre Simon Laplace attended a school in the village run at a Benedictine priory, his father intending that he be ordained in the Roman Catholic Church. At sixteen, to further his fathers intention, he was sent to the University of Caen to read theology, at the university, he was mentored by two enthusiastic teachers of mathematics, Christophe Gadbled and Pierre Le Canu, who awoke his zeal for the subject. Here Laplaces brilliance as a mathematician was recognised and while still at Caen he wrote a memoir Sur le Calcul integral aux differences infiniment petites et aux differences finies. About this time, recognizing that he had no vocation for the priesthood, in this connection reference may perhaps be made to the statement, which has appeared in some notices of him, that he broke altogether with the church and became an atheist. Laplace did not graduate in theology but left for Paris with a letter of introduction from Le Canu to Jean le Rond dAlembert who at time was supreme in scientific circles. According to his great-great-grandson, dAlembert received him rather poorly, and to get rid of him gave him a mathematics book

20.
Calorimeter
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A calorimeter is an object used for calorimetry, or the process of measuring the heat of chemical reactions or physical changes as well as heat capacity. Differential scanning calorimeters, isothermal microcalorimeters, titration calorimeters and accelerated rate calorimeters are among the most common types, a simple calorimeter just consists of a thermometer attached to a metal container full of water suspended above a combustion chamber. To find the enthalpy change per mole of a substance A in a reaction between two substances A and B, the substances are added to a calorimeter and the initial and final temperatures are noted. Multiplying the temperature change by the mass and specific heat capacities of the substances gives a value for the energy given off or absorbed during the reaction, dividing the energy change by how many moles of A were present gives its enthalpy change of reaction. This method is used primarily in teaching as it describes the theory of calorimetry. It does not account for the loss through the container or the heat capacity of the thermometer and container itself. The name calorimeter was made up by Antoine Lavoisier, in 1780, he used a guinea pig in his experiments with this device to measure heat production. The heat from the guinea pigs respiration melted snow surrounding the calorimeter, showing that respiratory gas exchange is combustion, an adiabatic calorimeter is a calorimeter used to examine a runaway reaction. Since the calorimeter runs in an environment, any heat generated by the material sample under test causes the sample to increase in temperature. No adiabatic calorimeter is fully adiabatic - some heat will be lost by the sample to the sample holder, a mathematical correction factor, known as the phi-factor, can be used to adjust the calorimetric result to account for these heat losses. The phi-factor is the ratio of the mass of the sample and sample holder to the thermal mass of the sample alone. A reaction calorimeter is a calorimeter in which a reaction is initiated within a closed insulated container. Reaction heats are measured and the heat is obtained by integrating heatflow versus time. This is the used in industry to measure heats since industrial processes are engineered to run at constant temperatures. Reaction calorimetry can also be used to determine maximum heat release rate for chemical process engineering, there are four main methods for measuring the heat in reaction calorimeter, The cooling/heating jacket controls either the temperature of the process or the temperature of the jacket. Heat is measured by monitoring the temperature difference between heat transfer fluid and the process fluid, in addition, fill volumes, specific heat, heat transfer coefficient have to be determined to arrive at a correct value. It is possible with this type of calorimeter to do reactions at reflux, the cooling/heating jacket controls the temperature of the process. Heat is measured by monitoring the heat gained or lost by the transfer fluid

21.
Phlogiston theory
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The phlogiston theory is a superseded scientific theory that postulated that a fire-like element called phlogiston is contained within combustible bodies and released during combustion. The name comes from the Ancient Greek φλογιστόν phlogistón, from φλόξ phlóx and it was first stated in 1667 by Johann Joachim Becher, and then put together more formally by Georg Ernst Stahl. The theory attempted to explain burning processes such as combustion and rusting, phlogisticated substances are substances that contain phlogiston and dephlogisticate when burned. Dephlogisticating is when the substance simply releases the phlogiston inside of it, growing plants then absorb this phlogiston, which is why air does not spontaneously combust and also why plant matter burns as well as it does. In the following quote, Becher described phlogiston as a process that explained combustion through a process that was opposite to that of oxygen. When air had become completely phlogisticated it would no longer serve to support combustion of any material, nor would a metal heated in it yield a calx, breathing was thought to take phlogiston out of the body. Joseph Blacks student Daniel Rutherford discovered nitrogen in 1772 and the pair used the theory to explain his results. The residue of air left after burning, in fact a mixture of nitrogen and carbon dioxide, was referred to as phlogisticated air. Conversely, when oxygen was first discovered, it was thought to be dephlogisticated air, capable of combining with more phlogiston and thus supporting combustion for longer than ordinary air. Empedocles had formulated the theory that there were four elements, water, earth, fire and air. Fire was thus thought of as a substance and burning was seen as a process of decomposition which applied only to compounds, however experience had shown that burning was not always accompanied by a loss of material and a better theory was needed to account for this. In 1667, Johann Joachim Becher published his book Physica subterranea, in his book, Becher eliminated fire, water, and air from the classical element model and replaced them with three forms of earth, terra lapidea, terra fluida, and terra pinguis. Terra pinguis was the element that imparted oily, sulphurous, or combustible properties, Becher believed that terra pinguis was a key feature of combustion and was released when combustible substances were burned. Becher did not have much to do with phlogiston theory as we know it now, bechers main contribution was the start of the theory itself, however much it was changed after him. Bechers idea was that combustible substances contain an ignitable matter, the terra pinguis, the term phlogiston itself was not something that Stahl invented. There is evidence that the word was used as early as 1606, the term was derived from a Greek word meaning to inflame. When the oxide was heated with a substance rich in phlogiston, such as charcoal, phlogiston was a definite substance, the same in all its combinations. Stahls first definition of phlogiston first appeared in his Zymotechnia fundamentalis and his most quoted definition was found in the treatise on chemistry entitled Fundamenta chymiae in 1723

22.
Caloric theory
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The caloric theory is an obsolete scientific theory that heat consists of a self-repellent fluid called caloric that flows from hotter bodies to colder bodies. Caloric was also thought of as a gas that could pass in. In the history of thermodynamics, the explanations of heat were thoroughly confused with explanations of combustion. After J. J. Becher and Georg Ernst Stahl introduced the theory of combustion in the 17th century. There is one version of the theory that was introduced by Antoine Lavoisier. Lavoisier developed the explanation of combustion in terms of oxygen in the 1770s, according to this theory, the quantity of this substance is constant throughout the universe, and it flows from warmer to colder bodies. Indeed, Lavoisier was one of the first to use a calorimeter to measure the changes during chemical reaction. In the 1780s, some believed that cold was a fluid, pierre Prévost argued that cold was simply a lack of caloric. Since heat was a substance in caloric theory, and therefore could neither be created nor destroyed. The introduction of the theory was also influenced by the experiments of Joseph Black related to the thermal properties of materials. Besides the caloric theory, another theory existed in the eighteenth century that could explain the phenomenon of heat. The two theories were considered to be equivalent at the time, but kinetic theory was the modern one, as it used a few ideas from atomic theory. Quite a number of successful explanations can be, and were and we can explain the cooling of a cup of tea in room temperature, caloric is self-repelling, and thus slowly flows from regions dense in caloric to regions less dense in caloric. We can explain the expansion of air under heat, caloric is absorbed into the air, sadi Carnot developed his principle of the Carnot cycle, which still forms the basis of heat engine theory, solely from the caloric viewpoint. However, one of the greatest apparent confirmations of the theory was Pierre-Simon Laplaces theoretical correction of Sir Isaac Newton’s calculation of the speed of sound. Newton had assumed an isothermal process, while Laplace, a calorist and he had found that boring a cannon repeatedly does not result in a loss of its ability to produce heat, and therefore no loss of caloric. This suggested that caloric could not be a conserved substance though the experimental uncertainties in his experiment were widely debated and his results were not seen as a threat to caloric theory at the time, as this theory was considered to be equivalent to the alternative kinetic theory. In fact, to some of his contemporaries, the added to the understanding of caloric theory

23.
John Dalton
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John Dalton FRS was an English chemist, physicist, and meteorologist. He is best known for his work in the development of modern atomic theory and his research into colour blindness. John Dalton was born into a Quaker family in Eaglesfield, near Cockermouth and he received his early education from his father and from Quaker John Fletcher, who ran a private school in the nearby village of Pardshaw Hall. With his family too poor to support him for long, he began to earn his living at the age of ten in the service of a wealthy local Quaker, Elihu Robinson. It is said he began teaching at a school at age 12. He joined his older brother Jonathan at age 15 in running a Quaker school in Kendal, around age 23 Dalton may have considered studying law or medicine, but his relatives did not encourage him, perhaps because being a Dissenter, he was barred from attending English universities. He acquired much scientific knowledge from informal instruction by John Gough, at age 27 he was appointed teacher of mathematics and natural philosophy at the New College in Manchester, a dissenting academy. He remained there until age 34, when the colleges worsening financial situation led him to resign his post and begin a new career as a tutor for mathematics. During his years in Kendal, Dalton contributed solutions of problems and questions on subjects to The Ladies Diary. In 1787 at age 21 he began to keep a diary in which, during the succeeding 57 years. He also rediscovered George Hadleys theory of atmospheric circulation around this time, Daltons first publication was Meteorological Observations and Essays at age 27 in 1793, which contained the seeds of several of his later discoveries. However, in spite of the originality of his treatment, little attention was paid to them by other scholars, a second work by Dalton, Elements of English Grammar, was published at age 35 in 1801. In fact, a shortage of colour perception in people had not even been formally described or officially noticed until Dalton wrote about his own. Since both he and his brother were colour blind, he recognized that this condition must be hereditary, examination of his preserved eyeball in 1995 demonstrated that Dalton actually had a less common kind of colour blindness, deuteroanopia, in which medium wavelength sensitive cones are missing. The altitude achieved was estimated using a barometer and this meant that, until the Ordnance Survey started publishing their maps for the Lake District in the 1860s, Dalton was one of the few sources of such information. Dalton was often accompanied by Jonathan Otley, who was one of the few other authorities on the heights of the Lake District mountains and he became both an assistant and a friend. These four essays were presented between 2 and 30 October 1801 and published in the Memoirs of the Literary and Philosophical Society of Manchester in 1802. It seems, therefore, that general laws respecting the absolute quantity and he thus enunciated Gay-Lussacs law, published in 1802 at age 36 by Joseph Louis Gay-Lussac

24.
Louis-Bernard Guyton de Morveau
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Louis-Bernard Guyton, Baron de Morveau was a French chemist and politician. He is credited with producing the first systematic method of chemical nomenclature, Guyton de Morveau was born in Dijon, where he served as a lawyer, then avocat général, of the Dijon parlement. In 1773, already interested in chemistry, he proposed use of acid gas for fumigation of buildings. However, chlorine was not well characterized at that time, in 1782 he resigned this post to dedicate himself to chemistry, collaborating on the Encyclopédie Méthodique and working for industrial applications. He performed various services in this role, and founded La Société des Mines et Verreries in Saint-Bérain-sur-Dheune. He developed the first system of chemical nomenclature, in 1783, he was elected a foreign member of the Royal Swedish Academy of Sciences and in 1788 a Fellow of the Royal Society. Although a member of the wing, he voted in favor of the execution of King Louis XVI. He himself flew in a balloon during the battle of Fleurus on 26 June 1794 and he was among the founders of the École Polytechnique and the École de Mars, and was a professor of mineralogy at the Polytechnique. He became a member of the Académie des sciences in chemistry, on 20 November 1795. In 1798 he married Claudine Picardet, a widowed friend. Under the Directory, he served on the Council of Five Hundred from 1797, elected from Ille-et-Vilaine, with Hugues Maret and Jean François Durande he also published the Élémens de chymie théorique et pratique. During his lifetime, Guyton de Morveau received the cross of the Legion of Honour and was made an Officer of the Legion of Honour for service to humanity and he was made a baron of the First French Empire in 1811. Guyton de Morveau died in Paris on 2 January 1816

25.
Claude Louis Berthollet
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Claude Louis Berthollet was a Savoyard-French chemist who became vice president of the French Senate in 1804. He is known for his contributions to theory of chemical equilibria via the mechanism of reverse chemical reactions. On a practical basis, Berthollet was the first to demonstrate the action of chlorine gas. Claude Louis Berthollet was born in Talloires, near Annecy, then part of the Duchy of Savoy and he started his studies at Chambéry and then in Turin where he graduated in medicine. Berthollets great new developments in works regarding chemistry made him, in a period of time. Berthollet, along with Antoine Lavoisier and others, devised a chemical nomenclature, or a system of names and he also carried out research into dyes and bleaches, being first to introduce the use of chlorine gas as a commercial bleach in 1785. He first produced a modern bleaching liquid in 1789 in his laboratory on the quay Javel in Paris, France, the resulting liquid, known as Eau de Javel, was a weak solution of sodium hypochlorite. Another strong chlorine oxidant and bleach which he investigated and was the first to produce, Berthollet first determined the elemental composition of the gas ammonia, in 1785. Berthollet was one of the first chemists to recognize the characteristics of a reverse reaction, Berthollet was engaged in a long-term battle with another French chemist Joseph Proust on the validity of the law of definite proportions. Although Proust proved his theory by accurate measurements, his theory was not immediately accepted partially due to Berthollets authority and his law was finally accepted when Berzelius confirmed it in 1811. But it was later that Berthollet was not completely wrong because there exists a class of compounds that do not obey the law of definite proportions. These non-stoichiometric compounds are also named berthollides in his honor, Berthollet was one of several scientists who went with Napoleon to Egypt, and was a member of the physics and natural history section of the Institut dÉgypte. In April,1789 Berthollet was elected a Fellow of the Royal Society of London, in 1801, he was elected a foreign member of the Royal Swedish Academy of Sciences. In 1809, Berthollet was elected a member first class of the Royal Institute of the Netherlands, predecessor of the Royal Netherlands Academy of Arts. He was elected an Honorary Fellow of the Royal Society of Edinburgh in 1820, Berthollet married Marguerite Baur in 1788. Berthollet was an accused of being an atheist and he died in Arcueil, France in 1822. Society of the Friends of Truth Satish, Kapoor, zeitschrift für anorganische und allgemeine Chemie. Between science and craft, The case of berthollet and dyeing, zeitschrift für anorganische und allgemeine Chemie

26.
International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker

27.
Wayback Machine
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The Internet Archive launched the Wayback Machine in October 2001. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet, the service enables users to see archived versions of web pages across time, which the archive calls a three dimensional index. Since 1996, the Wayback Machine has been archiving cached pages of websites onto its large cluster of Linux nodes and it revisits sites every few weeks or months and archives a new version. Sites can also be captured on the fly by visitors who enter the sites URL into a search box, the intent is to capture and archive content that otherwise would be lost whenever a site is changed or closed down. The overall vision of the machines creators is to archive the entire Internet, the name Wayback Machine was chosen as a reference to the WABAC machine, a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. These crawlers also respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached, to overcome inconsistencies in partially cached websites, Archive-It. Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers, when the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. Snapshots usually become more than six months after they are archived or, in some cases, even later. The frequency of snapshots is variable, so not all tracked website updates are recorded, Sometimes there are intervals of several weeks or years between snapshots. After August 2008 sites had to be listed on the Open Directory in order to be included. As of 2009, the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month, the growth rate reported in 2003 was 12 terabytes/month, the data is stored on PetaBox rack systems manufactured by Capricorn Technologies. In 2009, the Internet Archive migrated its customized storage architecture to Sun Open Storage, in 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing. The index driving the classic Wayback Machine only has a bit of material past 2008. In January 2013, the company announced a ground-breaking milestone of 240 billion URLs, in October 2013, the company announced the Save a Page feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries, as of December 2014, the Wayback Machine contained almost nine petabytes of data and was growing at a rate of about 20 terabytes each week. Between October 2013 and March 2015 the websites global Alexa rank changed from 162 to 208, in a 2009 case, Netbula, LLC v. Chordiant Software Inc. defendant Chordiant filed a motion to compel Netbula to disable the robots. Netbula objected to the motion on the ground that defendants were asking to alter Netbulas website, in an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No.02 C3293,65 Fed. 673, a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network

28.
Springer Science+Business Media
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Springer also hosts a number of scientific databases, including SpringerLink, Springer Protocols, and SpringerImages. Book publications include major works, textbooks, monographs and book series. Springer has major offices in Berlin, Heidelberg, Dordrecht, on 15 January 2015, Holtzbrinck Publishing Group / Nature Publishing Group and Springer Science+Business Media announced a merger. In 1964, Springer expanded its business internationally, opening an office in New York City, offices in Tokyo, Paris, Milan, Hong Kong, and Delhi soon followed. The academic publishing company BertelsmannSpringer was formed after Bertelsmann bought a majority stake in Springer-Verlag in 1999, the British investment groups Cinven and Candover bought BertelsmannSpringer from Bertelsmann in 2003. They merged the company in 2004 with the Dutch publisher Kluwer Academic Publishers which they bought from Wolters Kluwer in 2002, Springer acquired the open-access publisher BioMed Central in October 2008 for an undisclosed amount. In 2009, Cinven and Candover sold Springer to two private equity firms, EQT Partners and Government of Singapore Investment Corporation, the closing of the sale was confirmed in February 2010 after the competition authorities in the USA and in Europe approved the transfer. In 2011, Springer acquired Pharma Marketing and Publishing Services from Wolters Kluwer, in 2013, the London-based private equity firm BC Partners acquired a majority stake in Springer from EQT and GIC for $4.4 billion. In 2014, it was revealed that Springer had published 16 fake papers in its journals that had been computer-generated using SCIgen, Springer subsequently removed all the papers from these journals. IEEE had also done the thing by removing more than 100 fake papers from its conference proceedings. In 2015, Springer retracted 64 of the papers it had published after it was found that they had gone through a fraudulent peer review process, Springer provides its electronic book and journal content on its SpringerLink site, which launched in 1996. SpringerProtocols is home to a collection of protocols, recipes which provide step-by-step instructions for conducting experiments in research labs, SpringerImages was launched in 2008 and offers a collection of currently 1.8 million images spanning science, technology, and medicine. SpringerMaterials was launched in 2009 and is a platform for accessing the Landolt-Börnstein database of research and information on materials, authorMapper is a free online tool for visualizing scientific research that enables document discovery based on author locations and geographic maps. The tool helps users explore patterns in scientific research, identify trends, discover collaborative relationships. While open-access publishing typically requires the author to pay a fee for copyright retention, for example, a national institution in Poland allows authors to publish in open-access journals without incurring any personal cost - but using public funds. Springer is a member of the Open Access Scholarly Publishers Association, the Academic Publishing Industry, A Story of Merger and Acquisition – via Northern Illinois University

29.
International Standard Serial Number
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An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication. The ISSN is especially helpful in distinguishing between serials with the same title, ISSN are used in ordering, cataloging, interlibrary loans, and other practices in connection with serial literature. The ISSN system was first drafted as an International Organization for Standardization international standard in 1971, ISO subcommittee TC 46/SC9 is responsible for maintaining the standard. When a serial with the content is published in more than one media type. For example, many serials are published both in print and electronic media, the ISSN system refers to these types as print ISSN and electronic ISSN, respectively. The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers, as an integer number, it can be represented by the first seven digits. The last code digit, which may be 0-9 or an X, is a check digit. Formally, the form of the ISSN code can be expressed as follows, NNNN-NNNC where N is in the set, a digit character. The ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, for calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, the modulus 11 of the sum must be 0. There is an online ISSN checker that can validate an ISSN, ISSN codes are assigned by a network of ISSN National Centres, usually located at national libraries and coordinated by the ISSN International Centre based in Paris. The International Centre is an organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, at the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept, where ISBNs are assigned to individual books, an ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an identifier associated with a serial title. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change, separate ISSNs are needed for serials in different media. Thus, the print and electronic versions of a serial need separate ISSNs. Also, a CD-ROM version and a web version of a serial require different ISSNs since two different media are involved, however, the same ISSN can be used for different file formats of the same online serial

During chemical reactions, bonds between atoms break and form, resulting in different substances with different properties. In a blast furnace, iron oxide, a compound, reacts with carbon monoxide to form iron, one of the chemical elements, and carbon dioxide.

One of Robert Boyle's notebooks (1690-1691) held by the Royal Society of London. The Royal Society archives holds 46 volumes of philosophical, scientific and theological papers by Boyle and seven volumes of his correspondence.

Muybridge's photographs of The Horse in Motion, 1878, were used to answer the question whether all four feet of a galloping horse are ever off the ground at the same time. This demonstrates a use of photography as an experimental tool in science.

The Industrial Revolution was the transition to new manufacturing processes in the period from about 1760 to sometime …

A Roberts loom in a weaving shed in 1835. Textiles were the leading industry of the Industrial Revolution and mechanized factories, powered by a central water wheel or steam engine, were the new workplace.